Generally, an intake system of a vehicle is to flow air into a cylinder, and includes a plenum, and an intake manifold. The plenum is where external air flows in from outside. The intake manifold has a runner for guiding the air of the plenum into the cylinder. When an engine's rpm is high, it is preferable that a length of the runner of the intake manifold is short, and when the engine's rpm is low, it is preferable that a length of the runner of the intake manifold becomes long. A system that controls the length of the runner based on engine rpm is usually called a variable intake system (VIS). However, existing variable intake systems have a number of drawbacks, including the loss of flow pressure or velocity within parts of the system. Such systems are also too large.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known in this country to a person of ordinary skill in the art.